Set a sane $PATH for virt-login-shell

The virt-login-shell binary shouldn't need to execute programs
relying on $PATH, but just in case set a fixed $PATH value
of /bin:/usr/bin

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
(cherry picked from commit d665003da1)

tools/virt-login-shell.c

@@ -212,6 +212,8 @@ main(int argc, char **argv)
         return EXIT_FAILURE;
     }
 
+    setenv("PATH", "/bin:/usr/bin", 1);
+
     virSetErrorFunc(NULL, NULL);
     virSetErrorLogPriorityFunc(NULL);