pgsql: Add proper errcodes to new error messages for read() failures

Add proper errcodes to new error messages for read() failures

Those would use the default ERRCODE_INTERNAL_ERROR, but for foreseeable
failures an errcode ought to be set, ERRCODE_DATA_CORRUPTED making the
most sense here.

While on the way, fix one errcode_for_file_access missing in origin.c
since the code has been created, and remove one assignment of errno to 0
before calling read(), as this was around to fit with what was present
before 811b6e36 where errno would not be set when not enough bytes are
read. I have noticed the first one, and Tom has pinged me about the
second one.

Author: Michael Paquier
Reported-by: Tom Lane
Discussion: https://postgr.es/m/27265.1531925836@sss.pgh.pa.us

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/e41d0a1090b75fed4c033c2e404643382348f88e

Modified Files
--------------
src/backend/access/transam/xlog.c | 10 ++++++----
src/backend/replication/logical/origin.c | 6 ++++--
src/backend/replication/logical/snapbuild.c | 12 ++++++++----
src/backend/replication/slot.c | 6 ++++--
src/backend/replication/walsender.c | 6 ++++--
src/backend/utils/cache/relmapper.c | 3 ++-
src/common/controldata_utils.c | 3 ++-
7 files changed, 30 insertions(+), 16 deletions(-)