Bump version to 1.23.0

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/Makefile b/Makefile
index 778a02f..b487f04 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
 VERSION = 1
 PATCHLEVEL = 23
 SUBLEVEL = 0
-EXTRAVERSION = .git
+EXTRAVERSION =
 NAME = Unnamed
 
 # *DOCUMENTATION*