powerpc/rtas: Fix typo of ibm,open-errinjct in RTAS filter

Commit bd59380c ("powerpc/rtas: Restrict RTAS requests from userspace")
introduced the following error when invoking the errinjct userspace
tool:

  [root@ltcalpine2-lp5 librtas]# errinjct open
  [327884.071171] sys_rtas: RTAS call blocked - exploit attempt?
  [327884.071186] sys_rtas: token=0x26, nargs=0 (called by errinjct)
  errinjct: Could not open RTAS error injection facility
  errinjct: librtas: open: Unexpected I/O error

The entry for ibm,open-errinjct in rtas_filter array has a typo where
the "j" is omitted in the rtas call name. After fixing this typo the
errinjct tool functions again as expected.

  [root@ltcalpine2-lp5 linux]# errinjct open
  RTAS error injection facility open, token = 1

Fixes: bd59380c ("powerpc/rtas: Restrict RTAS requests from userspace")
Cc: stable@vger.kernel.org
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201208195434.8289-1-tyreld@linux.ibm.com

arch/powerpc/kernel/rtas.c

@@ -957,7 +957,7 @@ static struct rtas_filter rtas_filters[] __ro_after_init = {
 	{ "ibm,display-message", -1, 0, -1, -1, -1 },
 	{ "ibm,errinjct", -1, 2, -1, -1, -1, 1024 },
 	{ "ibm,close-errinjct", -1, -1, -1, -1, -1 },
-	{ "ibm,open-errinct", -1, -1, -1, -1, -1 },
+	{ "ibm,open-errinjct", -1, -1, -1, -1, -1 },
 	{ "ibm,get-config-addr-info2", -1, -1, -1, -1, -1 },
 	{ "ibm,get-dynamic-sensor-state", -1, 1, -1, -1, -1 },
 	{ "ibm,get-indices", -1, 2, 3, -1, -1 },