Remove res/ari/* content during 'make clean'.

'make clean' and 'make distclean' can leave behind .o files in the
res/ari/ directory. One observed consequence of this is that running
Asterisk with MALLOC_DEBUG can cause Asterisk to crash immediately on
startup sometimes.

By ensuring that we are making a clean build, we can be sure that stale
files are not being included in the build and causing problems when
build options should have caused files to be re-built.

ASTERISK-25683 #close
Reported by yaron nahum

Change-Id: I1f48baa904d2468eddeefb42ee68a56af7adc7b7

res/Makefile

@@ -81,6 +81,7 @@ clean::
 	rm -f stasis/*.[oi] stasis/*.gcda stasis/*.gcno
 	rm -f parking/*.[oi] parking/*.gcda parking/*.gcno
 	rm -f stasis_recording/*.[oi] stasis_recording/*.gcda stasis_recording/*.gcno
+	rm -f res/ari/*.[oi] res/ari/*.gcda res/ari/*.gcno
 
 $(if $(filter res_parking,$(EMBEDDED_MODS)),modules.link,res_parking.so): $(subst .c,.o,$(wildcard parking/*.c))
 $(subst .c,.o,$(wildcard parking/*.c)): _ASTCFLAGS+=$(call MOD_ASTCFLAGS,res_parking)