Simplify patch to darshan-apmpi.c

This also fixes errors when running 'make distcheck'

Author: wkliao

darshan-runtime/lib/Makefile.am

@@ -105,7 +105,7 @@ if BUILD_APMPI_MODULE
                   -I$(apmpi_root) -I$(apmpi_root)/lib
 endif
 darshan-apmpi.c:
-	$(LN_S) $(apmpi_root)/lib/darshan-apmpi.c .
+	$(LN_S) $(top_srcdir)/../modules/patched_darshan-apmpi.c $@
 
 libdarshan_la_SOURCES  = $(C_SRCS)
 libdarshan_la_LIBADD   = -lpthread -lrt -lz -ldl $(DARSHAN_LUSTRE_LD_FLAGS)

modules/Makefile.am

@@ -3,23 +3,7 @@
 #
 # @configure_input@
 
-apmpi_c_src = $(srcdir)/autoperf/apmpi/lib/darshan-apmpi.c
-apmpi_c_patched = $(srcdir)/patched_darshan-apmpi.c
-apmpi_c_saved = $(srcdir)/saved_darshan-apmpi.c
-apmpi_c_orig = $(srcdir)/orig_darshan-apmpi.c
-
-# Rule to apply the patch
-$(apmpi_c_saved): $(apmpi_c_src) $(apmpi_c_patched)
-	cp -f $(apmpi_c_src) $(apmpi_c_saved)
-	cp -f $(apmpi_c_patched) $(apmpi_c_src)
-	touch $(apmpi_c_saved)
-
-BUILT_SOURCES = $(apmpi_c_saved)
-
-EXTRA_DIST = patched_darshan-apmpi.c orig_darshan-apmpi.c
-
-CLEANFILES = $(apmpi_c_saved)
-
-clean-local:
-	cp -f -p $(apmpi_c_orig) $(apmpi_c_src)
+EXTRA_DIST = patched_darshan-apmpi.c \
+             orig_darshan-apmpi.c \
+             autoperf