selftests/powerpc: Fix uninitialized variable warning

Patch fixes uninitialized variable warning in bad_accesses test
which causes the selftests build to fail in older distibutions

bad_accesses.c: In function ‘bad_access’:
bad_accesses.c:52:9: error: ‘x’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
printf("Bad - no SEGV! (%c)\n", x);
^
cc1: all warnings being treated as errors

Signed-off-by: Harish <[e-mail]>
Signed-off-by: Michael Ellerman <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

tools/testing/selftests/powerpc/mm/bad_accesses.c

···
 
 int bad_access(char *p, bool write)
 {
-	char x;
+	char x = 0;
 
 	fault_code = 0;
 	fault_addr = 0;