[klibc] gzip: Fix typo CONFIG_KLIB_ZIP -> CONFIG_KLIBC_ZIP

We were using CONFIG_KLIB_ZIP in a couple of places where we
meant to use CONFIG_KLIBC_ZIP. I also added the option to
the defconfig.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
diff --git a/defconfig b/defconfig
index c10a4f5..04b98e9 100644
--- a/defconfig
+++ b/defconfig
@@ -1,6 +1,7 @@
 CONFIG_KLIBC=y
 CONFIG_KLIBC_ERRLIST=y
 CONFIG_KLIBC_ZLIB=y
+# CONFIG_KLIBC_ZIP is not set
 # i386 option
 CONFIG_REGPARM=y
 # ARM options
diff --git a/usr/gzip/Kbuild b/usr/gzip/Kbuild
index 64fae04..9bbf0a4 100644
--- a/usr/gzip/Kbuild
+++ b/usr/gzip/Kbuild
@@ -10,8 +10,8 @@
 always := gunzip zcat
 
 # Optional ZIP support
-gzip-$(CONFIG_KLIB_ZIP)   += zip.o deflate.o trees.o bits.o
-cflags-$(CONFIG_KLIB_ZIP) += -DSUPPORT_ZIP
+gzip-$(CONFIG_KLIBC_ZIP)   += zip.o deflate.o trees.o bits.o
+cflags-$(CONFIG_KLIBC_ZIP) += -DSUPPORT_ZIP
 EXTRA_KLIBCCFLAGS := $(cflags-y)
 
 # Additionally linked targets