parisc: includecheck fix: signal.c

fix the following 'make includecheck' warning:

  arch/parisc/kernel/signal.c: linux/compat.h is included more than once.
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>

arch/parisc/kernel/signal.c

@@ -35,7 +35,6 @@
 #include <asm/asm-offsets.h>
 
 #ifdef CONFIG_COMPAT
-#include <linux/compat.h>
 #include "signal32.h"
 #endif