package/zstd: Prefer dynamically linked tool

If the libzstd DSO is available, then link the tool
against it.

Signed-off-by: Norbert Lange <nolange79@gmail.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>

package/zstd/zstd.mk

@@ -49,6 +49,13 @@ ZSTD_BUILD_LIBS = lib
 ZSTD_INSTALL_LIBS = install-static install-shared
 endif
 
+# prefer zstd-dll unless no library is available
+ifeq ($(BR2_STATIC_LIBS),y)
+ZSTD_BUILD_PROG_TARGET = zstd-release
+else
+ZSTD_BUILD_PROG_TARGET = zstd-dll
+endif
+
 # The HAVE_THREAD flag is read by the 'programs' makefile but not by  the 'lib'
 # one. Building a multi-threaded binary with a static library (which defaults
 # to single-threaded) gives a runtime error when compressing files.
@@ -68,7 +75,7 @@ define ZSTD_BUILD_CMDS
 	$(TARGET_MAKE_ENV) $(TARGET_CONFIGURE_OPTS) $(MAKE) $(ZSTD_OPTS) \
 		-C $(@D)/lib $(ZSTD_BUILD_LIBS) libzstd.pc
 	$(TARGET_MAKE_ENV) $(TARGET_CONFIGURE_OPTS) $(MAKE) $(ZSTD_OPTS) \
-		-C $(@D) zstd-release
+		-C $(@D)/programs $(ZSTD_BUILD_PROG_TARGET)
 endef
 
 define ZSTD_INSTALL_STAGING_CMDS