[MIPS] ARC: Fix several compiler warnings.

  CC      arch/mips/arc/init.o
arch/mips/arc/init.c: In function 'prom_init':
arch/mips/arc/init.c:27: warning: ISO C90 forbids mixed declarations and code
arch/mips/arc/init.c:35: warning: format ‘%08lx’ expects type ‘long unsigned int’, but argument 2 has type 'ULONG'
arch/mips/arc/init.c:28: warning: unused variable 'c'
arch/mips/arc/init.c:27: warning: unused variable ‘cnt’
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

arch/mips/arc/init.c

@@ -23,16 +23,16 @@ LONG *_prom_argv, *_prom_envp;
 void __init prom_init(void)
 {
 	PSYSTEM_PARAMETER_BLOCK pb = PROMBLOCK;
+
 	romvec = ROMVECTOR;
-	ULONG cnt;
-	CHAR c;
 
 	prom_argc = fw_arg0;
 	_prom_argv = (LONG *) fw_arg1;
 	_prom_envp = (LONG *) fw_arg2;
 
 	if (pb->magic != 0x53435241) {
-		printk(KERN_CRIT "Aieee, bad prom vector magic %08lx\n", pb->magic);
+		printk(KERN_CRIT "Aieee, bad prom vector magic %08lx\n",
+		       (unsigned long) pb->magic);
 		while(1)
 			;
 	}