powerpc/eeh: Fix /proc/ppc64/eeh creation

Since commit 188917e183cf9ad0374b571006d0fc6d48a7f447, /proc/ppc64 is a
symlink to /proc/powerpc/. That means that creating /proc/ppc64/eeh will
end up with a unaccessible file, that is not listed under /proc/powerpc/
and, then, not listed under /proc/ppc64/.

Creating /proc/powerpc/eeh fixes that problem and maintain the
compatibility intended with the ppc64 symlink.

Signed-off-by: Thadeu Lima de Souza Cascardo <[e-mail]>
Signed-off-by: Benjamin Herrenschmidt <[e-mail]>
Cc: <[e-mail]> [3.x]

arch/powerpc/platforms/pseries/eeh.c

···
 static int __init eeh_init_proc(void)
 {
 	if (machine_is(pseries))
-		proc_create("ppc64/eeh", 0, NULL, &proc_eeh_operations);
+		proc_create("powerpc/eeh", 0, NULL, &proc_eeh_operations);
 	return 0;
 }
 __initcall(eeh_init_proc);