perl: Fix uClibc handling

Configuration scripts expect the libc identifier to be "uclibc" in case we're using it,
OpenWrt provides "uClibc". Oh well...

Signed-off-by: Marcel Denia <naoir@gmx.net>

lang/perl/Makefile

@@ -97,7 +97,7 @@ define Build/Configure
 	                                -Dowrt:target_cross='$(TARGET_CROSS)' \
 	                                -Dowrt:cflags='$(TARGET_CFLAGS_PERL) $(TARGET_CPPFLAGS_PERL)' \
 	                                -Dowrt:ldflags='-rdynamic $(TARGET_LDFLAGS)' \
-	                                -Dowrt:libc=$(CONFIG_LIBC) \
+	                                -Dowrt:libc=$(subst uClibc,uclibc,$(CONFIG_LIBC)) \
 	                                -Dowrt:ipv6=$(if $($(CONFIG_IPV6)),define,undef) \
 	                                -Dowrt:threads=$(if $(CONFIG_PERL_THREADS),yes,no) \
 	                                -Dowrt:staging_dir='$(STAGING_DIR)' \