x86/asm: Fix SETZ size enqcmds() build failure

When building under GCC 4.9 and 5.5:

arch/x86/include/asm/special_insns.h: Assembler messages:
arch/x86/include/asm/special_insns.h:286: Error: operand size mismatch for `setz'

Change the type to "bool" for condition code arguments, as documented.

Fixes: 7f5933f81bd8 ("x86/asm: Add an enqcmds() wrapper for the ENQCMDS instruction")
Co-developed-by: Arnd Bergmann <[e-mail]>
Signed-off-by: Arnd Bergmann <[e-mail]>
Signed-off-by: Kees Cook <[e-mail]>
Signed-off-by: Borislav Petkov <[e-mail]>
Link: https://lkml.kernel.org/r/[e-mail]

arch/x86/include/asm/special_insns.h

···
 {
 	const struct { char _[64]; } *__src = src;
 	struct { char _[64]; } __iomem *__dst = dst;
-	int zf;
+	bool zf;
 
 	/*
 	 * ENQCMDS %(rdx), rax