Tweak the shell scripting for descending into and building subdirs.

In general, use this:
	@for dir in $(SUBDIRS) ; do \
		if [ -d $$dir ] ; then \
			(cd $$dir && $(MAKE)) || exit 1; \
		fi \
	done

Basically, silently skip missing subdirs but generate an error and stop if
there's a compilation or install problem.
This was done inconsistantly before.  In once case, a missing subdir was
causing us to go into an infinte loop!

Makefile

@@ -7,7 +7,9 @@ SUBDIRS = src progs
 
 default: $(TOP)/configs/current
 	@for dir in $(SUBDIRS) ; do \
-		(cd $$dir ; $(MAKE)) || exit 1 ; \
+		if [ -d $$dir ] ; then \
+			(cd $$dir && $(MAKE)) || exit 1 ; \
+		fi \
 	done
 
 
@@ -16,7 +18,9 @@ doxygen:
 
 clean:
 	@for dir in $(SUBDIRS) ; do \
-		(cd $$dir ; $(MAKE) clean) ; \
+		if [ -d $$dir ] ; then \
+			(cd $$dir && $(MAKE) clean) ; \
+		fi \
 	done
 
 
@@ -34,9 +38,12 @@ realclean:
 
 install:
 	@for dir in $(SUBDIRS) ; do \
-		(cd $$dir ; $(MAKE) install) || exit 1 ; \
+		if [ -d $$dir ] ; then \
+			(cd $$dir && $(MAKE) install) || exit 1 ; \
+		fi \
 	done
 
+
 # DirectFBGL module installation
 linux-directfb-install:
 	cd src/mesa/drivers/directfb && $(MAKE) install

progs/Makefile

@@ -17,7 +17,7 @@ message:
 subdirs:
 	@for dir in $(SUBDIRS) ; do \
 		if [ -d $$dir ] ; then \
-			(cd $$dir ; $(MAKE)) || exit 1 ; \
+			(cd $$dir && $(MAKE)) || exit 1 ; \
 		fi \
 	done
 
@@ -27,6 +27,6 @@ install:
 clean:
 	@for dir in $(SUBDIRS) tests ; do \
 		if [ -d $$dir ] ; then \
-			(cd $$dir ; $(MAKE) clean) ; \
+			(cd $$dir && $(MAKE) clean) ; \
 		fi \
 	done

src/Makefile

@@ -17,14 +17,14 @@ message:
 subdirs:
 	@for dir in $(SUBDIRS) ; do \
 		if [ -d $$dir ] ; then \
-			(cd $$dir ; $(MAKE)) || exit 1 ; \
+			(cd $$dir && $(MAKE)) || exit 1; \
 		fi \
 	done
 
 install:
 	@for dir in $(SUBDIRS) ; do \
 		if [ -d $$dir ] ; then \
-			(cd $$dir ; $(MAKE) install) || exit 1 ; \
+			(cd $$dir && $(MAKE) install) || exit 1 ; \
 		fi \
 	done
 
@@ -35,6 +35,6 @@ $(TOP)/$(LIB_DIR):
 clean:
 	@for dir in $(SUBDIRS) ; do \
 		if [ -d $$dir ] ; then \
-			(cd $$dir ; $(MAKE) clean) ; \
+			(cd $$dir && $(MAKE) clean) ; \
 		fi \
 	done

src/mesa/drivers/dri/Makefile

@@ -14,21 +14,25 @@ $(TOP)/$(LIB_DIR):
 
 
 subdirs:
-	echo $(DRI_DIRS)
 	@for dir in $(DRI_DIRS) ; do \
-		echo $$dir ; \
-		(cd $$dir && $(MAKE)) || exit 1; \
+		if [ -d $$dir ] ; then \
+			(cd $$dir && $(MAKE)) || exit 1 ; \
+		fi \
 	done
 
 
 install:
 	@for dir in $(DRI_DIRS) ; do \
-		(cd $$dir && $(MAKE) install) || exit 1; \
+		if [ -d $$dir ] ; then \
+			(cd $$dir && $(MAKE) install) || exit 1 ; \
+		fi \
 	done
 
 
 clean:
 	@for dir in $(DRI_DIRS) ; do \
-		(cd $$dir && $(MAKE) clean) ; \
+		if [ -d $$dir ] ; then \
+			(cd $$dir && $(MAKE) clean ; \
+		fi \
 	done
 	-rm -f common/*.o