powerpc/process: Fix sparse address space warnings

This patch fixes the following warnings, which are leftovers
from when __get_user() was replaced by probe_kernel_address().

arch/powerpc/kernel/process.c:1287:22: warning: incorrect type in argument 2 (different address spaces)
arch/powerpc/kernel/process.c:1287:22:    expected void const *src
arch/powerpc/kernel/process.c:1287:22:    got unsigned int [noderef] <asn:1>*<noident>
arch/powerpc/kernel/process.c:1319:21: warning: incorrect type in argument 2 (different address spaces)
arch/powerpc/kernel/process.c:1319:21:    expected void const *src
arch/powerpc/kernel/process.c:1319:21:    got unsigned int [noderef] <asn:1>*<noident>

Fixes: 7b051f66 ("powerpc: Use probe_kernel_address in show_instructions")
Reviewed-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[mpe: Split out of larger patch]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/kernel/process.c

@@ -1281,7 +1281,7 @@ static void show_instructions(struct pt_regs *regs)
 #endif
 
 		if (!__kernel_text_address(pc) ||
-		     probe_kernel_address((unsigned int __user *)pc, instr)) {
+		    probe_kernel_address((const void *)pc, instr)) {
 			pr_cont("XXXXXXXX ");
 		} else {
 			if (regs->nip == pc)
@@ -1323,7 +1323,7 @@ void show_user_instructions(struct pt_regs *regs)
 			pr_info("%s[%d]: code: ", current->comm, current->pid);
 		}
 
-		if (probe_kernel_address((unsigned int __user *)pc, instr)) {
+		if (probe_kernel_address((const void *)pc, instr)) {
 			pr_cont("XXXXXXXX ");
 		} else {
 			if (regs->nip == pc)