t1002: modernize outdated conditional

Tests in this script use an unusual and hard to reason about
conditional construct

    if expression; then false; else :; fi

Change them to use more idiomatic construct:

    ! expression

Cc: Christian Couder  <christian.couder@gmail.com>
Cc: Hariom Verma <hariom18599@gmail.com>
Signed-off-by: Nsengiyumva  Wilberforce <nsengiyumvawilberforce@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t1002-read-tree-m-u-2way.sh

@@ -154,7 +154,7 @@ test_expect_success \
      read_tree_u_must_succeed --reset -u $treeH &&
      echo frotz frotz >frotz &&
      git update-index --add frotz &&
-     if read_tree_u_must_succeed -m -u $treeH $treeM; then false; else :; fi'
+     ! read_tree_u_must_succeed -m -u $treeH $treeM'
 
 test_expect_success \
     '9 - conflicting addition.' \
@@ -163,7 +163,7 @@ test_expect_success \
      echo frotz frotz >frotz &&
      git update-index --add frotz &&
      echo frotz >frotz &&
-     if read_tree_u_must_succeed -m -u $treeH $treeM; then false; else :; fi'
+     ! read_tree_u_must_succeed -m -u $treeH $treeM'
 
 test_expect_success \
     '10 - path removed.' \
@@ -186,7 +186,7 @@ test_expect_success \
      echo rezrov >rezrov &&
      git update-index --add rezrov &&
      echo rezrov rezrov >rezrov &&
-     if read_tree_u_must_succeed -m -u $treeH $treeM; then false; else :; fi'
+     ! read_tree_u_must_succeed -m -u $treeH $treeM'
 
 test_expect_success \
     '12 - unmatching local changes being removed.' \
@@ -194,7 +194,7 @@ test_expect_success \
      read_tree_u_must_succeed --reset -u $treeH &&
      echo rezrov rezrov >rezrov &&
      git update-index --add rezrov &&
-     if read_tree_u_must_succeed -m -u $treeH $treeM; then false; else :; fi'
+     ! read_tree_u_must_succeed -m -u $treeH $treeM'
 
 test_expect_success \
     '13 - unmatching local changes being removed.' \
@@ -203,7 +203,7 @@ test_expect_success \
      echo rezrov rezrov >rezrov &&
      git update-index --add rezrov &&
      echo rezrov >rezrov &&
-     if read_tree_u_must_succeed -m -u $treeH $treeM; then false; else :; fi'
+     ! read_tree_u_must_succeed -m -u $treeH $treeM'
 
 cat >expected <<EOF
 -100644 X 0	nitfol
@@ -251,7 +251,7 @@ test_expect_success \
      read_tree_u_must_succeed --reset -u $treeH &&
      echo bozbar bozbar >bozbar &&
      git update-index --add bozbar &&
-     if read_tree_u_must_succeed -m -u $treeH $treeM; then false; else :; fi'
+     ! read_tree_u_must_succeed -m -u $treeH $treeM'
 
 test_expect_success \
     '17 - conflicting local change.' \
@@ -260,7 +260,7 @@ test_expect_success \
      echo bozbar bozbar >bozbar &&
      git update-index --add bozbar &&
      echo bozbar bozbar bozbar >bozbar &&
-     if read_tree_u_must_succeed -m -u $treeH $treeM; then false; else :; fi'
+     ! read_tree_u_must_succeed -m -u $treeH $treeM'
 
 test_expect_success \
     '18 - local change already having a good result.' \
@@ -316,7 +316,7 @@ test_expect_success \
      echo bozbar >bozbar &&
      git update-index --add bozbar &&
      echo gnusto gnusto >bozbar &&
-     if read_tree_u_must_succeed -m -u $treeH $treeM; then false; else :; fi'
+     ! read_tree_u_must_succeed -m -u $treeH $treeM'
 
 # Also make sure we did not break DF vs DF/DF case.
 test_expect_success \