doc PG 17 relnotes: fix pg_stat_reset_shared quoting

Reported-by: torikoshia

Discussion: https://postgr.es/m/8ab708436c369d47fcbb23a8ad775ea7@oss.nttdata.com

Backpatch-through: master

Author: bmomjian

doc/src/sgml/release-17.sgml

@@ -647,7 +647,7 @@ Author: Michael Paquier <michael@paquier.xyz>
 
 <listitem>
 <para>
-Allow pg_stat_reset_shared("slru") to clear SLRU statistics (Atsushi Torikoshi)
+Allow pg_stat_reset_shared('slru') to clear SLRU statistics (Atsushi Torikoshi)
 </para>
 
 <para>