gitpkgv.bbclass: fix versioning with multiple repos

gitpkgv class is supposed to use SRCREV_FORMAT variable to define
how to smoosh together revision info from multiple repos that are
used in a single recipe. It is incorrectly repeating the rev hash
for the first repo instead of including the rev from each listed repo.

Example:

  SRC_URI = "git://some-server/purple.git;destsuffix=git/purple;name=purple"
  SRC_URI += "git://other-server/blue.git;destsuffix=git/blue;name=blue"
  SRCREV_purple = "${AUTOREV}"
  SRCREV_blue = "${AUTOREV}"
  SRCREV_FORMAT = "purple_blue"

Suppose gitpkgv calculates "67+ea121ea" for purple repo,
and "123+feef001" for blue repo. This should result in a
package version with them joined together like so:

"67+ea121ea_123+feef001"

It didn't. Instead the git hash part for the first repo got repeated:

"67+ea121ea_123+ea121ea"

Fix this by looking in the right place for the git revisions of 2nd
(and following) repos when assembling the full version string.

Signed-off-by: S. Lockwood-Childs <sjl@vctlabs.com>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>

meta-oe/classes/gitpkgv.bbclass

@@ -110,9 +110,9 @@ def get_git_pkgv(d, use_tags):
                             d, quiet=True).strip()
                         ver = gitpkgv_drop_tag_prefix(output)
                     except Exception:
-                        ver = "0.0-%s-g%s" % (commits, rev[:7])
+                        ver = "0.0-%s-g%s" % (commits, vars['rev'][:7])
                 else:
-                    ver = "%s+%s" % (commits, rev[:7])
+                    ver = "%s+%s" % (commits, vars['rev'][:7])
 
                 format = format.replace(name, ver)