update-ref --stdin: narrow scope of err strbuf
Making the strbuf local in each function that needs to print errors
saves the reader from having to think about action at a distance,
such as
* errors piling up and being concatenated with no newline between
them
* errors unhandled in one function, to be later handled in another
* concurrency issues, if this code starts using threads some day
No functional change intended.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Reviewed-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>