pvm_sys_dump_active: utilize proper systemd syntax

Was noticing this warning in the journal:
/lib/systemd/system/op-clear-sys-dump-active@.service:17: Ignoring unknown escape sequences: "busctl set-property xyz.openbmc_project.BIOSConfigManager     /xyz/openbmc_project/bios_config/manager xyz.openbmc_project.BIOSConfig.Manager     PendingAttributes a{s\(sv\)} 1 pvm_sys_dump_active     xyz.openbmc_project.BIOSConfig.Manager.AttributeType.Enumeration s Disabled"

A bit of internet searching pointed out that systemd requires two
backslashes

Tested:
- Verified services still work as expected and we no longer get the
  above warning.

Signed-off-by: Andrew Geissler <geissonator@yahoo.com>
Change-Id: I234d17ee32c66fef874ee8dfc8037990e5d7e6fc
diff --git a/service_files/op-clear-sys-dump-active@.service.in b/service_files/op-clear-sys-dump-active@.service.in
index c2f5ea2..f318eae 100644
--- a/service_files/op-clear-sys-dump-active@.service.in
+++ b/service_files/op-clear-sys-dump-active@.service.in
@@ -13,7 +13,7 @@
 ExecStart=/bin/sh -c \
   "busctl set-property xyz.openbmc_project.BIOSConfigManager \
    /xyz/openbmc_project/bios_config/manager xyz.openbmc_project.BIOSConfig.Manager \
-   PendingAttributes a{s\(sv\)} 1 pvm_sys_dump_active \
+   PendingAttributes a{s\\(sv\\)} 1 pvm_sys_dump_active \
    xyz.openbmc_project.BIOSConfig.Manager.AttributeType.Enumeration s Disabled"
 
 [Install]
diff --git a/service_files/op-enter-mpreboot@.service.in b/service_files/op-enter-mpreboot@.service.in
index 8e60caa..a46caf4 100644
--- a/service_files/op-enter-mpreboot@.service.in
+++ b/service_files/op-enter-mpreboot@.service.in
@@ -18,7 +18,7 @@
 ExecStart=/bin/sh -c \
   "busctl set-property xyz.openbmc_project.BIOSConfigManager \
    /xyz/openbmc_project/bios_config/manager xyz.openbmc_project.BIOSConfig.Manager \
-   PendingAttributes a{s\(sv\)} 1 pvm_sys_dump_active \
+   PendingAttributes a{s\\(sv\\)} 1 pvm_sys_dump_active \
    xyz.openbmc_project.BIOSConfig.Manager.AttributeType.Enumeration s Enabled"
 ExecStart=/usr/bin/openpower-proc-control enterMpReboot
 ExecStart=/bin/mkdir -p /run/openbmc/