stress-branch: initialize branch_jmps to zero

When branch_jmps is not initialized shift ends up being a garbage
value which can then make idx garbage when an undefined shift size
occurs causing a SIGSEGV when indexing into the counts array. Fix
this by initializing branch_jmps to zero.

Fixes: 082483d ("stress-branch: add --branch-jumps option and double branch targets")

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>

Author: ColinIanKing

stress-branch.c

@@ -375,7 +375,7 @@ static int OPTIMIZE2 stress_branch(stress_args_t *args)
 	register uint32_t idx = 0;
 	register const void *label_next = labels[idx];
 	register uint32_t shift = 26;
-	size_t branch_jumps;
+	size_t branch_jumps = 0;
 
 	(void)stress_setting_get("branch-jumps", &branch_jumps);
 	shift -= branch_jumps;