log-manager: enable non-standard path for local tests

Enable the log-manager to be launched with a path other than
`/var/phosphor-logging` to allow it to be ran on a development system
for test purposes.  This required some refactoring throughout as to
how paths were handled.

Tested:

After running tests, `/tmp/phosphor-logging` is populated with
entries.  Launching `./builddir/phosphor-log-manager
/tmp/phosphor-logging`, the log-manager will have the entries on
dbus:

```
$ busctl --user tree xyz.openbmc_project.Logging
└─ /xyz
  └─ /xyz/openbmc_project
    └─ /xyz/openbmc_project/logging
      ├─ /xyz/openbmc_project/logging/entry
      │ ├─ /xyz/openbmc_project/logging/entry/100
      │ ├─ /xyz/openbmc_project/logging/entry/101
      │ ├─ /xyz/openbmc_project/logging/entry/102
      │ ├─ /xyz/openbmc_project/logging/entry/103
```

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I84968edeed0dcf73aaf8bb653060b6d3400b9b7b
diff --git a/extensions/openpower-pels/meson.build b/extensions/openpower-pels/meson.build
index fb6282b..db57568 100644
--- a/extensions/openpower-pels/meson.build
+++ b/extensions/openpower-pels/meson.build
@@ -68,6 +68,7 @@
     'severity.cpp',
     'user_header.cpp',
     'temporary_file.cpp',
+    '../../paths.cpp',
     '../../util.cpp',
     extra_sources,
 )
@@ -86,7 +87,7 @@
 libpel_lib = static_library(
     'pel',
     libpel_sources,
-    'paths.cpp', # paths is separate because it is overridden during test.
+    'pel_paths.cpp', # paths is separate because it is overridden during test.
     include_directories: include_directories('../..', '../../gen'),
     cpp_args: extra_args,
     dependencies: [