x86: relocs ELF handling - use SELFMAG instead of numeric constant

Signed-off-by: NCyrill Gorcunov <gorcunov@gmail.com>
Cc: akpm@linux-foundation.org
Cc: hpa@zytor.com
Cc: mingo@elte.hu
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

arch/x86/boot/compressed/relocs.c

@@ -191,7 +191,7 @@ static void read_ehdr(FILE *fp)
 		die("Cannot read ELF header: %s\n",
 			strerror(errno));
 	}
-	if (memcmp(ehdr.e_ident, ELFMAG, 4) != 0) {
+	if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0) {
 		die("No ELF magic\n");
 	}
 	if (ehdr.e_ident[EI_CLASS] != ELFCLASS32) {