pmcstat.8: Add a missing ERRORS section header

MFC after:	3 days
Sponsored by:	fme AG

usr.sbin/pmcstat/pmcstat.8

@@ -23,7 +23,7 @@
 .\" out of the use of this software, even if advised of the possibility of
 .\" such damage.
 .\"
-.Dd April 15, 2026
+.Dd August 14, 2026
 .Dt PMCSTAT 8
 .Os
 .Sh NAME
@@ -530,7 +530,7 @@ kernel or the runtime loader).
 The number of samples that were associated with an executable
 with an unrecognized object format.
 .El
-.Pp
+.Sh ERRORS
 .Ex -std
 .Sh COMPATIBILITY
 Due to the limitations of the