Fixed GNUmakefile target in devel build

Closes #488.

gpAux/Makefile

@@ -115,7 +115,7 @@ LOADERSDEVPATH=$(GPROOT_DEV)$(LOADERSDIR)
 endif
 
 # files generated by 'configure'
-ISCONFIG=../GNUmakefile
+ISCONFIG=$(GPPGDIR)/GNUmakefile
 
 
 ##
@@ -268,7 +268,7 @@ aix5_ppc_64_CONFIG_SHELL=/usr/bin/bash
 aix5_ppc_32_CONFIG_SHELL=/usr/bin/bash
 BLD_CONFIG_SHELL=$($(BLD_ARCH)_CONFIG_SHELL)
 
-../GNUmakefile : $(GPPGDIR)/configure  env.sh
+$(GPPGDIR)/GNUmakefile : $(GPPGDIR)/configure  env.sh
 	rm -rf $(INSTLOC)
 	mkdir -p $(GPPGDIR) 
 	$(MAKE) -C $(GPPGDIR)/src/bin/gpfdist/ext BLD_TOP=$(BLD_TOP)
@@ -513,8 +513,7 @@ devel : BUILDDIR=Debug
 devel : ISCONFIG=$(BUILDDIR)/GNUmakefile
 devel : gccVersionCheck HOMEDEP Debug/GNUmakefile
 else
-devel : ISCONFIG=../GNUmakefile
-devel : gccVersionCheck HOMEDEP $(GPPGDIR)/GNUmakefile
+devel : gccVersionCheck HOMEDEP $(ISCONFIG)
 endif
 	$(BUILD_STEPS)
 
@@ -534,7 +533,6 @@ dist : BUILDDIR=Release
 dist : ISCONFIG=$(BUILDDIR)/GNUmakefile
 dist : gccVersionCheck GPROOTDEP RECONFIG Release/GNUmakefile
 else
-dist : ISCONFIG=../GNUmakefile
 dist : gccVersionCheck GPROOTDEP RECONFIG $(ISCONFIG)
 endif
 	$(BUILD_STEPS)