SubmittingPatches: remove dq from commit reference

Quoting SZEDER Gábor[1], SubmittingPatches is simply wrong: our de-facto standard format for referencing other commits does not enclose the subject in a pair of double-quotes: $ git log v2.24.0 |grep -E '[0-9a-f]{7} \("' |wc -l 785 $ git log v2.24.0 |grep -E '[0-9a-f]{7} \([^"]' |wc -l 2276 Those double-quotes don't add any value to the references, but they result in weird looking references for 1083 of our commits whose subject lines happen to end with double-quotes, e.g.: f23a465132 ("hashmap_get{,_from_hash} return "struct hashmap_entry *"", 2019-10-06) and without those unnecessary pair of double-quotes we would have ~3000 more commits whose summary would fit on a single line. Remove references to the enclosing double-quotes from SubmittingPatches since our de-facto standard for referencing commits does not actually use them. [1]: cf. <20191114011048.GS4348@szeder.dev> Signed-off-by: Denton Liu <liu.denton@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>