Replace redundant yread() with read_in_full() in fast-import.
Replace redundant yread() with read_in_full() in fast-import.

Prior to git having read_in_full() fast-import used its own private
function yread to perform the header reading task.  No sense in
keeping that around now that read_in_full is a public, stable
function.

Signed-off-by: Shawn O. Pearce <f01032651c12a22b2103346ba96b3b6b231f9d3c@spearce.org>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git