upload: short circuit when nothing is pending
upload: short circuit when nothing is pending

When nothing is pending, most of this code is already short-circuited.
Hoist the single check up to make this more obvious/slightly faster.

Change-Id: Iec3a7e08eacd23a7c5f964900d5776bf5252c804

couchbasedeps/git-repo,wavecomp/git-repo,lipro-yocto/git-repo,nuclearmistake/repo,gabbayo/git-repo,11NJ/git-repo,dodocat/git-repo,TheQtCompany/git-repo,qioixiy/git-repo,couchbasedeps/git-repo,chenzilin/git-repo,lewixliu/git-repo,nuclearmistake/repo,gabbayo/git-repo,lipro-yocto/git-repo,chenzilin/git-repo,TheQtCompany/git-repo,aosp-mirror/tools_repo,GerritCodeReview/git-repo,chzhong/git-repo,chzhong/git-repo,mer-tools/git-repo,qioixiy/git-repo,frogbywyplay/git-repo,GerritCodeReview/git-repo,codetutil/git-repo,codetutil/git-repo,mer-tools/git-repo,11NJ/git-repo,wavecomp/git-repo,lewixliu/git-repo,dodocat/git-repo,aosp-mirror/tools_repo,frogbywyplay/git-repo