t9130-git-svn-authors-file.sh: use the $( ... ) construct for command substitution

The Git CodingGuidelines prefer the $(...) construct for command
substitution instead of using the backquotes `...`.

The backquoted form is the traditional method for command
substitution, and is supported by POSIX.  However, all but the
simplest uses become complicated quickly.  In particular, embedded
command substitutions and/or the use of double quotes require
careful escaping with the backslash character.

The patch was generated by:

for _f in $(find . -name "*.sh")
do
	perl -i -pe 'BEGIN{undef $/;} s/`(.+?)`/\$(\1)/smg'  "${_f}"
done

and then carefully proof-read.

Signed-off-by: Elia Pinto <gitter.spiros@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t9130-git-svn-authors-file.sh

@@ -26,7 +26,7 @@ test_expect_success 'start import with incomplete authors file' '
 test_expect_success 'imported 2 revisions successfully' '
 	(
 		cd x
-		test "`git rev-list refs/remotes/git-svn | wc -l`" -eq 2 &&
+		test "$(git rev-list refs/remotes/git-svn | wc -l)" -eq 2 &&
 		git rev-list -1 --pretty=raw refs/remotes/git-svn | \
 		  grep "^author BBBBBBB BBBBBBB <bb@example\.com> " &&
 		git rev-list -1 --pretty=raw refs/remotes/git-svn~1 | \
@@ -43,7 +43,7 @@ test_expect_success 'continues to import once authors have been added' '
 	(
 		cd x
 		git svn fetch --authors-file=../svn-authors &&
-		test "`git rev-list refs/remotes/git-svn | wc -l`" -eq 4 &&
+		test "$(git rev-list refs/remotes/git-svn | wc -l)" -eq 4 &&
 		git rev-list -1 --pretty=raw refs/remotes/git-svn | \
 		  grep "^author DDDDDDD DDDDDDD <dd@example\.com> " &&
 		git rev-list -1 --pretty=raw refs/remotes/git-svn~1 | \
@@ -73,8 +73,8 @@ tmp_config_get () {
 test_expect_success 'failure happened without negative side effects' '
 	(
 		cd aa-work &&
-		test 6 -eq "`tmp_config_get svn-remote.svn.branches-maxRev`" &&
-		test 6 -eq "`tmp_config_get svn-remote.svn.tags-maxRev`"
+		test 6 -eq "$(tmp_config_get svn-remote.svn.branches-maxRev)" &&
+		test 6 -eq "$(tmp_config_get svn-remote.svn.tags-maxRev)"
 	)
 	'
 
@@ -86,8 +86,8 @@ test_expect_success 'fetch continues after authors-file is fixed' '
 	(
 		cd aa-work &&
 		git svn fetch --authors-file=../svn-authors &&
-		test 8 -eq "`tmp_config_get svn-remote.svn.branches-maxRev`" &&
-		test 8 -eq "`tmp_config_get svn-remote.svn.tags-maxRev`"
+		test 8 -eq "$(tmp_config_get svn-remote.svn.branches-maxRev)" &&
+		test 8 -eq "$(tmp_config_get svn-remote.svn.tags-maxRev)"
 	)
 	'