locking/atomics: Don't assume that scripts are executable

patch(1) doesn't set the x bit on files.  So if someone downloads and
applies patch-4.21.xz, their kernel won't build.  Fix that by executing
/bin/sh.

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

scripts/atomic/gen-atomics.sh

@@ -13,7 +13,7 @@ gen-atomic-long.sh              asm-generic/atomic-long.h
 gen-atomic-fallback.sh          linux/atomic-fallback.h
 EOF
 while read script header; do
-	${ATOMICDIR}/${script} ${ATOMICTBL} > ${LINUXDIR}/include/${header}
+	/bin/sh ${ATOMICDIR}/${script} ${ATOMICTBL} > ${LINUXDIR}/include/${header}
 	HASH="$(sha1sum ${LINUXDIR}/include/${header})"
 	HASH="${HASH%% *}"
 	printf "// %s\n" "${HASH}" >> ${LINUXDIR}/include/${header}