kbuild: move $(strip ) to suffix-search definition

Move $(strip ...) to the callee from the callers of suffix-search. It
shortens the code slightly. Adding a space after a comma will not be
a matter. I also dropped parentheses from single character variables.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

scripts/Makefile.lib

@@ -45,16 +45,16 @@ obj-y		:= $(filter-out %/, $(obj-y))
 endif
 
 # Expand $(foo-objs) $(foo-y) by calling $(call suffix-search,foo.o,-objs -y)
-suffix-search = $(foreach s,$(2),$($(1:.o=$s)))
+suffix-search = $(strip $(foreach s, $2, $($(1:.o=$s))))
 # If $(foo-objs), $(foo-y), $(foo-m), or $(foo-) exists, foo.o is a composite object
-multi-search = $(sort $(foreach m,$(1), $(if $(strip $(call suffix-search,$(m),$(2) -)), $(m))))
+multi-search = $(sort $(foreach m, $1, $(if $(call suffix-search, $m, $2 -), $m)))
 multi-obj-y := $(call multi-search,$(obj-y),-objs -y)
 multi-obj-m := $(call multi-search,$(obj-m),-objs -y -m)
 multi-obj-ym := $(multi-obj-y) $(multi-obj-m)
 
 # Replace multi-part objects by their individual parts,
 # including built-in.a from subdirectories
-real-search = $(foreach m,$(1), $(if $(strip $(call suffix-search,$(m),$(2) -)),$(call suffix-search,$(m),$(2)),$(m)))
+real-search = $(foreach m, $1, $(if $(call suffix-search, $m, $2 -), $(call suffix-search, $m, $2), $m))
 real-obj-y := $(call real-search, $(obj-y),-objs -y)
 real-obj-m := $(call real-search, $(obj-m),-objs -y -m)