use condition statement to use only .NOTPARALLEL when target map is specified.

git-svn-id: http://root.cern.ch/svn/root/trunk@9104 27541ba8-7e3a-0410-8455-c3a389f83636

Makefile

@@ -336,7 +336,9 @@ endif
                 $(patsubst %,clean-%,$(MODULES)) \
                 $(patsubst %,distclean-%,$(MODULES))
 
-.NOTPARALLEL:   map Makefile
+ifneq ($(findstring map, $(MAKECMDGOALS)),)
+.NOTPARALLEL:
+endif
 
 all:            rootexecs