powerpc/kgdb: Removed kmalloc returned value cast

Signed-off-by: Alex Grad <alex.grad@gmail.com>
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>

arch/powerpc/kernel/kgdb.c

@@ -159,7 +159,7 @@ static int kgdb_singlestep(struct pt_regs *regs)
 	if (user_mode(regs))
 		return 0;
 
-	backup_current_thread_info = (struct thread_info *)kmalloc(sizeof(struct thread_info), GFP_KERNEL);
+	backup_current_thread_info = kmalloc(sizeof(struct thread_info), GFP_KERNEL);
 	/*
 	 * On Book E and perhaps other processors, singlestep is handled on
 	 * the critical exception stack.  This causes current_thread_info()