build-aux/version.sh: Use SUSv2 compatible sed expression.

SUSv2 doesn't seem to allow semicolons to separate commands;
only newlines work. The old version didn't work with /bin/sed
on Solaris although it did with /usr/xpg4/bin/sed.

build-aux/version.sh

@@ -18,5 +18,7 @@ sed -n 's/LZMA_VERSION_STABILITY_ALPHA/alpha/
 	s/^#define LZMA_VERSION_[MPS][AIT][AJNT][A-Z]* //p' \
 	src/liblzma/api/lzma/version.h \
 	| tr '\n' '|' \
-	| sed 's/|/./; s/|/./; s/|//g' \
+	| sed 's/|/./
+		s/|/./
+		s/|//g' \
 	| tr -d '\r\n'