lrzsz: fix repeated target install

Closes #4165

Use ln -sf in case destination already exists from an earlier install,
and use install -D rather than cp while we're at it.

Based on patch by Hector Oron <hector.oron@gmail.com>

Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

CHANGES

@@ -60,6 +60,7 @@
 	#3631: Error while compiling with Xorg
 	#3925: midori not getting compile
 	#4045: Add support for downloading i386 toolchains from codesourcery
+	#4165: lrzsz-fix-symlink-at-rebuild.patch
 	#4171: makedevs-unused-but-set-variable.patch
 	#4183: Codesourcery toolchain download site has changed
 

package/lrzsz/lrzsz.mk

@@ -36,10 +36,10 @@ define LRZSZ_BUILD_HOOKS
 endef
 
 define LRZSZ_INSTALL_TARGET_CMDS
-	cp $(@D)/src/lrz $(TARGET_DIR)/usr/bin/rz
-	cp $(@D)/src/lsz $(TARGET_DIR)/usr/bin/sz
-	ln -s rz $(TARGET_DIR)/usr/bin/lrz
-	ln -s sz $(TARGET_DIR)/usr/bin/lsz
+	$(INSTALL) -m 0755 -D $(@D)/src/lrz $(TARGET_DIR)/usr/bin/rz
+	$(INSTALL) -m 0755 -D $(@D)/src/lsz $(TARGET_DIR)/usr/bin/sz
+	ln -sf rz $(TARGET_DIR)/usr/bin/lrz
+	ln -sf sz $(TARGET_DIR)/usr/bin/lsz
 endef
 
 define LRZSZ_CLEAN_CMDS