kbuild: fix typo in modpost

Reported by a Fedora user when they tried to build some out of tree module..
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

scripts/Makefile.modpost

@@ -40,7 +40,7 @@ include scripts/Kbuild.include
 include scripts/Makefile.lib
 
 kernelsymfile := $(objtree)/Module.symvers
-modulesymfile := $(KBUILD_EXTMOD)/Modules.symvers
+modulesymfile := $(KBUILD_EXTMOD)/Module.symvers
 
 # Step 1), find all modules listed in $(MODVERDIR)/
 __modules := $(sort $(shell grep -h '\.ko' /dev/null $(wildcard $(MODVERDIR)/*.mod)))