s390: move the install rule to arch/s390/Makefile

Currently, the install target in arch/s390/Makefile descends into
arch/s390/boot/Makefile to invoke the shell script, but there is no
good reason to do so.

arch/s390/Makefile can run the shell script directly.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://lore.kernel.org/r/20210729142338.446002-1-masahiroy@kernel.orgSigned-off-by: Heiko Carstens <hca@linux.ibm.com>

arch/s390/Makefile

@@ -142,7 +142,8 @@ all: bzImage
 KBUILD_IMAGE	:= $(boot)/bzImage
 
 install:
-	$(Q)$(MAKE) $(build)=$(boot) $@
+	sh -x $(srctree)/$(boot)/install.sh $(KERNELRELEASE) $(KBUILD_IMAGE) \
+	      System.map "$(INSTALL_PATH)"
 
 bzImage: vmlinux
 	$(Q)$(MAKE) $(build)=$(boot) $(boot)/$@

arch/s390/boot/Makefile

@@ -70,7 +70,3 @@ $(obj)/compressed/vmlinux: $(obj)/startup.a FORCE
 
 $(obj)/startup.a: $(OBJECTS) FORCE
 	$(call if_changed,ar)
-
-install:
-	sh -x  $(srctree)/$(obj)/install.sh $(KERNELRELEASE) $(obj)/bzImage \
-	      System.map "$(INSTALL_PATH)"