kbuild: Fix reference to vermagic.h

It's "include/linux/vermagic.h", not "include/vermagic.h"

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>

scripts/Makefile.modpost

@@ -18,7 +18,7 @@
 
 # Step 3 is used to place certain information in the module's ELF
 # section, including information such as:
-#   Version magic (see include/vermagic.h for full details)
+#   Version magic (see include/linux/vermagic.h for full details)
 #     - Kernel release
 #     - SMP is CONFIG_SMP
 #     - PREEMPT is CONFIG_PREEMPT