t/t6015-rev-list-show-all-parents.sh: use the $( ... ) construct for command substitution

diff --git a/GIT-VERSION-GEN b/GIT-VERSION-GEN
index 4478007b0178807c6113066cc709630770ca199a..904265b2c1add2aa9d974a18e8a63ab13038c070 100755 (executable)
--- a/GIT-VERSION-GEN
+++ b/GIT-VERSION-GEN
@@ -1,7 +1,7 @@
 #!/bin/sh
 
 GVF=GIT-VERSION-FILE
-DEF_VER=v2.7.0-rc1
+DEF_VER=v2.7.0-rc2
 
 LF='
 '