osmo-release.sh: Drop whitespace after = when parsing LIBVERSION

As a result whitespace ended up in some variables and then command
"expr" was not happy about it.
It was spotted because src/coding/Makefile.am had some whitespacing.
Since it's the only one, let's drop the whitespace there too to have
similar line in all Makefile.am files.

Change-Id: I33afef5e4ef9eb36de81274533f46598ba9a0edb
diff --git a/src/coding/Makefile.am b/src/coding/Makefile.am
index c001c13..f47fe45 100644
--- a/src/coding/Makefile.am
+++ b/src/coding/Makefile.am
@@ -1,7 +1,7 @@
 # This is _NOT_ the library release version, it's an API version.
 # Please read Chapter 6 "Library interface versions" of the libtool
 # documentation before making any modification
-LIBVERSION = 1:1:1
+LIBVERSION=1:1:1
 
 AM_CPPFLAGS = \
 	-I"$(top_srcdir)/include" \