Makefile.am: Fix mixed tabs and spaces

In some cases I noticed build is failing possibly due to
mixed tabs and spaces in Makefile.

Signed-off-by: Kun Yi <kunyi731@gmail.com>
Change-Id: I5d724b9f48b583b50c71b3e03884c88f9eb8d6de
diff --git a/Makefile.am b/Makefile.am
index dfb112d..68cbd87 100755
--- a/Makefile.am
+++ b/Makefile.am
@@ -27,10 +27,10 @@
 phosphor_settings_manager_CXXFLAGS = \
 	$(PHOSPHOR_DBUS_INTERFACES_CFLAGS) \
 	$(SDBUSPLUS_CFLAGS) \
-        $(PHOSPHOR_LOGGING_CFLAGS)
+	$(PHOSPHOR_LOGGING_CFLAGS)
 
 phosphor_settings_manager_LDADD = \
 	$(PHOSPHOR_DBUS_INTERFACES_LIBS) \
 	$(SDBUSPLUS_LIBS) \
-        $(PHOSPHOR_LOGGING_LIBS) \
+	$(PHOSPHOR_LOGGING_LIBS) \
 	-lstdc++fs