Get ‘./configure; make -C src emacs’ to work

Without this fix, lib/fcntl.h isn't built in time (Bug#20894).
* lib-src/Makefile.in (../lib/libgnu.a):
* src/Makefile.in ($(lib)/libgnu.a): Build all, not libgnu.a.

lib-src/Makefile.in

@@ -350,7 +350,7 @@ TAGS: etags${EXEEXT}
 	etags *.[ch]
 
 ../lib/libgnu.a: $(config_h)
-	$(MAKE) -C ../lib libgnu.a
+	$(MAKE) -C ../lib all
 
 regex.o: $(srcdir)/../src/regex.c $(srcdir)/../src/regex.h $(config_h)
 	$(AM_V_CC)$(CC) -c $(CPP_CFLAGS) $<

src/Makefile.in

@@ -556,7 +556,7 @@ globals.h: gl-stamp; @true
 $(ALLOBJS): globals.h
 
 $(lib)/libgnu.a: $(config_h)
-	$(MAKE) -C $(lib) libgnu.a
+	$(MAKE) -C $(lib) all
 
 ## We have to create $(etc) here because init_cmdargs tests its
 ## existence when setting Vinstallation_directory (FIXME?).