Simplify micro-revision dependency rules

The Automake variable OBJEXT is automatically adjusted to the correct
object file extension for the target platform.

src/common/include.am

@@ -78,10 +78,8 @@ LIBOR_A_SOURCES = \
   $(threads_impl_source)				\
   $(readpassphrase_source)
 
-src/common/src_common_libor_testing_a-log.o \
-  src/common/src_common_libor_testing_a-log.obj \
-  src/common/log.o \
-  src/common/log.obj : micro-revision.i
+src/common/src_common_libor_testing_a-log.$(OBJEXT) \
+  src/common/log.$(OBJEXT): micro-revision.i
 
 LIBOR_CRYPTO_A_SOURCES = \
   src/common/aes.c		\

src/or/include.am

@@ -93,10 +93,8 @@ src_or_libtor_testing_a_SOURCES = $(LIBTOR_A_SOURCES)
 src_or_tor_SOURCES = src/or/tor_main.c
 AM_CPPFLAGS += -I$(srcdir)/src/or -Isrc/or
 
-src/or/tor_main.o \
-  src/or/tor_main.obj \
-  src/or/src_or_tor_cov-tor_main.o \
-  src/or/src_or_tor_cov-tor_main.obj : micro-revision.i
+src/or/tor_main.$(OBJEXT) \
+  src/or/src_or_tor_cov-tor_main.$(OBJEXT): micro-revision.i
 
 AM_CPPFLAGS += -DSHARE_DATADIR="\"$(datadir)\""		\
 		-DLOCALSTATEDIR="\"$(localstatedir)\""	\