package/libcap: avoid calling /sbin/ldconfig during the host build

There is snippet in the install path that calls /sbin/ldconfig
when a variable FAKEROOT is empty

  install-shared-cap: install-common-cap $(MINCAPLIBNAME)
          install -m 0755 $(MINCAPLIBNAME) $(FAKEROOT)$(LIBDIR)/$(MINCAPLIBNAME)
          ln -sf $(MINCAPLIBNAME) $(FAKEROOT)$(LIBDIR)/$(MAJCAPLIBNAME)
          ln -sf $(MAJCAPLIBNAME) $(FAKEROOT)$(LIBDIR)/$(CAPLIBNAME)
  ifeq ($(FAKEROOT),)
          -/sbin/ldconfig
  endif

And this variable is defined when DESTDIR is used, so still define prefix
but use the DESTDIR in the host build as well to avoid calling ldconfig
at all.

Signed-off-by: Charles Hardin <charles.hardin@chargepoint.com>

Author: chardin-cpi

package/libcap/libcap.mk

@@ -56,7 +56,7 @@ HOST_LIBCAP_MAKE_FLAGS = \
 	DYNAMIC=yes \
 	GOLANG=no \
 	lib=lib \
-	prefix=$(HOST_DIR) \
+	prefix= \
 	RAISE_SETFCAP=no
 
 define HOST_LIBCAP_BUILD_CMDS
@@ -65,7 +65,8 @@ define HOST_LIBCAP_BUILD_CMDS
 endef
 
 define HOST_LIBCAP_INSTALL_CMDS
-	$(HOST_MAKE_ENV) $(MAKE) -C $(@D) $(HOST_LIBCAP_MAKE_FLAGS) install
+	$(HOST_MAKE_ENV) $(MAKE) -C $(@D) $(HOST_LIBCAP_MAKE_FLAGS) \
+		DESTDIR=$(HOST_DIR) install
 endef
 
 $(eval $(generic-package))