configure: Minor fixes

Don't add extraneous characters when SHRLIB_VERSION or GNU_TARGET
are empty.  The addprefix or addsuffix functions only include the
prefix/suffix part if the list argument is not empty.

This fixes issues naming libCap5.so at build-time.

configure/os/CONFIG.Common.UnixCommon

@@ -20,8 +20,8 @@ OBJ = .o
 LIB_PREFIX = lib
 LIB_SUFFIX = .a
 SHRLIB_SUFFIX_BASE = .so
-SHRLIB_SUFFIX = $(SHRLIB_SUFFIX_BASE).$(SHRLIB_VERSION)
-LOADABLE_SHRLIB_SUFFIX = $(SHRLIB_SUFFIX_BASE).$(LOADABLE_SHRLIB_VERSION)
+SHRLIB_SUFFIX = $(SHRLIB_SUFFIX_BASE)$(addprefix .,$(SHRLIB_VERSION))
+LOADABLE_SHRLIB_SUFFIX = $(SHRLIB_SUFFIX_BASE)$(addprefix .,$(LOADABLE_SHRLIB_VERSION))
 LOADABLE_SHRLIB_PREFIX = lib
 
 #-------------------------------------------------------

configure/os/CONFIG.Common.linux-arm

@@ -17,7 +17,7 @@ ifeq ($(BUILD_CLASS),CROSS)
 
     # prefix of compiler tools
     CMPLR_SUFFIX =
-    CMPLR_PREFIX = $(GNU_TARGET)-
+    CMPLR_PREFIX = $(addsuffix -,$(GNU_TARGET))
 
     # Provide a link-time path for shared libraries
     SHRLIBDIR_RPATH_LDFLAGS_YES += $(SHRLIB_DEPLIB_DIRS:%=-Wl,-rpath-link,%)