x86_32: fix %cx -> %ecx mismatch on testl To get rid of: arch/x86/kernel/entry_32.S: Assembler messages: arch/x86/kernel/entry_32.S:600: Warning: using `%ecx' instead of `%cx' due to `l' suffix Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>