build: drop flto option to workaround gcc issue

main.o swampd-util.o  ./.libs/libswampd.a -lstdc++fs -lphosphor_logging
-lsdbusplus -lsystemd -lphosphor_dbus
00:59:59 | lto1: internal compiler error: in add_symbol_to_partition_1,
at lto/lto-partition.c:154

Signed-off-by: Patrick Venture <venture@google.com>
Change-Id: I387d1530ff7daaa217dce980e357ea612f7ddfdb
diff --git a/Makefile.am b/Makefile.am
index 45b26d4..2daf76f 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -76,8 +76,7 @@
 	$(SDBUSPLUS_CFLAGS) \
 	$(PHOSPHOR_DBUS_INTERFACES_CFLAGS) \
 	$(PHOSPHOR_LOGGING_CFLAGS) \
-	$(CODE_COVERAGE_CXXFLAGS) \
-	-flto
+	$(CODE_COVERAGE_CXXFLAGS)
 
 libswampd_la_SOURCES = \
 	notimpl/readonly.cpp \
@@ -130,7 +129,6 @@
 	$(PHOSPHOR_DBUS_INTERFACES_CFLAGS) \
 	$(PHOSPHOR_LOGGING_CFLAGS) \
 	$(LIBIPMID_CFLAGS) \
-	$(CODE_COVERAGE_CXXFLAGS) \
-	-flto
+	$(CODE_COVERAGE_CXXFLAGS)
 
 SUBDIRS = . test