Fix unnecessary false in CLEANLIBS

Author: nobu

lib/mkmf.rb

@@ -2510,16 +2510,19 @@ def create_makefile(target, srcprefix = nil)
     sodir = $extout ? '$(TARGET_SO_DIR)' : '$(RUBYARCHDIR)'
     n = '$(TARGET_SO_DIR)$(TARGET)'
     cleanobjs = ["$(OBJS)"]
+    cleanlibs = []
     if $extmk
       %w[bc i s].each {|ex| cleanobjs << "$(OBJS:.#{$OBJEXT}=.#{ex})"}
     end
     if target
       config_string('cleanobjs') {|t| cleanobjs << t.gsub(/\$\*/, "$(TARGET)#{deffile ? '-$(arch)': ''}")}
+      cleanlibs << '$(TARGET_SO)'
     end
+    config_string('cleanlibs') {|t| cleanlibs << t.gsub(/\$\*/) {n}}
     conf << "\
 TARGET_SO_DIR =#{$extout ? " $(RUBYARCHDIR)/" : ''}
 TARGET_SO     = $(TARGET_SO_DIR)$(DLLIB)
-CLEANLIBS     = #{'$(TARGET_SO) ' if target}#{config_string('cleanlibs') {|t| t.gsub(/\$\*/) {n}}}
+CLEANLIBS     = #{cleanlibs.join(' ')}
 CLEANOBJS     = #{cleanobjs.join(' ')} *.bak
 TARGET_SO_DIR_TIMESTAMP = #{timestamp_file(sodir, target_prefix)}
 " #"