ARM: 7555/1: kexec: fix segment memory addresses check

Commit c564df4d (ARM: 7540/1: kexec:
Check segment memory addresses) added a safety check with accidentally
reversed condition, and broke kexec functionality on ARM. Fix this.
Acked-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NAaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

arch/arm/kernel/machine_kexec.c

@@ -45,10 +45,9 @@ int machine_kexec_prepare(struct kimage *image)
 	for (i = 0; i < image->nr_segments; i++) {
 		current_segment = &image->segment[i];
 
-		err = memblock_is_region_memory(current_segment->mem,
-						current_segment->memsz);
-		if (err)
-			return - EINVAL;
+		if (!memblock_is_region_memory(current_segment->mem,
+					       current_segment->memsz))
+			return -EINVAL;
 
 		err = get_user(header, (__be32*)current_segment->buf);
 		if (err)