build-sys: re-enable 'dist' build

The 'build-sys: re-enable out of tree build' commit
failed to also address the 'dist' target errors.

include/Makefile.am

@@ -1,4 +1,5 @@
 dist_noinst_HEADERS = \
 	c.h \
 	nls.h \
+	strutils.h \
 	xalloc.h

proc/Makefile.am

@@ -16,7 +16,7 @@ libprocps_la_LDFLAGS = \
 	-no-undefined \
 	-Wl,--version-script=$(top_srcdir)/proc/libprocps.sym
 
-EXTRA_DIST = library.map
+EXTRA_DIST = libprocps.sym
 
 pkgconfigdir = $(libdir)/pkgconfig
 pkgconfig_DATA = libprocps.pc