Fix BufferStorage11::getLatestStorage not finding the latest buffer.
Fix BufferStorage11::getLatestStorage not finding the latest buffer.

If there are only buffers with data revision 0, getLatestStorage will skip
over them.  Fixed the if statement so that it will always find a buffer if
one exists.

BUG=angle:644

Change-Id: I24fc426383c9ae18b7ccf2f8937a9daa7a071ebe
Reviewed-on: https://chromium-review.googlesource.com/198826
Reviewed-by: Jamie Madill <7e492b4f1c8458024932de3ba475cbf015424c30@chromium.org>
Tested-by: Geoff Lang <b6fc25fe0362055230985c05cbfa8adb741ccc0f@chromium.org>

nandhanurrevanth/angle,mrobinson/rust-angle,csa7mdm/angle,nandhanurrevanth/angle,mikolalysenko/angle,mybios/angle,csa7mdm/angle,larsbergstrom/angle,bsergean/angle,xin3liang/platform_external_chromium_org_third_party_angle,MSOpenTech/angle,geekboxzone/lollipop_external_chromium_org_third_party_angle,ghostoy/angle,larsbergstrom/angle,jgcaaprom/android_external_chromium_org_third_party_angle,mikolalysenko/angle,xin3liang/platform_external_chromium_org_third_party_angle,mrobinson/rust-angle,xin3liang/platform_external_chromium_org_third_party_angle,bsergean/angle,ecoal95/angle,MSOpenTech/angle,ecoal95/angle,mybios/angle,ppy/angle,MIPS/external-chromium_org-third_party-angle,ecoal95/angle,mrobinson/rust-angle,ppy/angle,crezefire/angle,csa7mdm/angle,vvuk/angle,ghostoy/angle,vvuk/angle,nandhanurrevanth/angle,mrobinson/rust-angle,MIPS/external-chromium_org-third_party-angle,ecoal95/angle,android-ia/platform_external_chromium_org_third_party_angle,MSOpenTech/angle,jgcaaprom/android_external_chromium_org_third_party_angle,jgcaaprom/android_external_chromium_org_third_party_angle,larsbergstrom/angle,ecoal95/angle,vvuk/angle,android-ia/platform_external_chromium_org_third_party_angle,android-ia/platform_external_chromium_org_third_party_angle,mlfarrell/angle,bsergean/angle,MSOpenTech/angle,bsergean/angle,domokit/waterfall,mybios/angle,geekboxzone/lollipop_external_chromium_org_third_party_angle,ghostoy/angle,mrobinson/rust-angle,xin3liang/platform_external_chromium_org_third_party_angle,crezefire/angle,MIPS/external-chromium_org-third_party-angle,mikolalysenko/angle,larsbergstrom/angle,mikolalysenko/angle,geekboxzone/lollipop_external_chromium_org_third_party_angle,crezefire/angle,nandhanurrevanth/angle,mlfarrell/angle,vvuk/angle,crezefire/angle,csa7mdm/angle,ppy/angle,mlfarrell/angle,ghostoy/angle,android-ia/platform_external_chromium_org_third_party_angle,mybios/angle,geekboxzone/lollipop_external_chromium_org_third_party_angle,MIPS/external-chromium_org-third_party-angle,ppy/angle,jgcaaprom/android_external_chromium_org_third_party_angle,mlfarrell/angle,domokit/waterfall