EDAC, octeon: Fix an uninitialized variable warning

Fix an uninitialized variable warning in the Octeon EDAC driver, as seen
in MIPS cavium_octeon_defconfig builds since v4.14 with Codescape GNU
Tools 2016.05-03:

  drivers/edac/octeon_edac-lmc.c In function ‘octeon_lmc_edac_poll_o2’:
  drivers/edac/octeon_edac-lmc.c:87:24: warning: ‘((long unsigned int*)&int_reg)[1]’ may \
    be used uninitialized in this function [-Wmaybe-uninitialized]
    if (int_reg.s.sec_err || int_reg.s.ded_err) {
                        ^
Iinitialise the whole int_reg variable to zero before the conditional
assignments in the error injection case.

Signed-off-by: James Hogan <jhogan@kernel.org>
Acked-by: David Daney <david.daney@cavium.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # 3.15+
Fixes: 1bc021e ("EDAC: Octeon: Add error injection support")
Link: http://lkml.kernel.org/r/20171113161206.20990-1-james.hogan@mips.com
Signed-off-by: Borislav Petkov <bp@suse.de>

drivers/edac/octeon_edac-lmc.c

@@ -78,6 +78,7 @@ static void octeon_lmc_edac_poll_o2(struct mem_ctl_info *mci)
 	if (!pvt->inject)
 		int_reg.u64 = cvmx_read_csr(CVMX_LMCX_INT(mci->mc_idx));
 	else {
+		int_reg.u64 = 0;
 		if (pvt->error_type == 1)
 			int_reg.s.sec_err = 1;
 		if (pvt->error_type == 2)