kbuild: remove redundant mkdir from ./Kbuild

These two targets are added to "targets".  Their directories are
automatically created.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

Kbuild

@@ -17,7 +17,6 @@ targets := kernel/bounds.s
 
 # We use internal kbuild rules to avoid the "is up to date" message from make
 kernel/bounds.s: kernel/bounds.c FORCE
-	$(Q)mkdir -p $(dir $@)
 	$(call if_changed_dep,cc_s_c)
 
 $(obj)/$(bounds-file): kernel/bounds.s FORCE
@@ -53,7 +52,6 @@ targets += arch/$(SRCARCH)/kernel/asm-offsets.s
 # We use internal kbuild rules to avoid the "is up to date" message from make
 arch/$(SRCARCH)/kernel/asm-offsets.s: arch/$(SRCARCH)/kernel/asm-offsets.c \
                                       $(obj)/$(timeconst-file) $(obj)/$(bounds-file) FORCE
-	$(Q)mkdir -p $(dir $@)
 	$(call if_changed_dep,cc_s_c)
 
 $(obj)/$(offsets-file): arch/$(SRCARCH)/kernel/asm-offsets.s FORCE