Fix typos.

Reviewed-by: Michael Paquier
Discussion: https://postgr.es/m/CA%2BhUKGJFWXmtYo6Frd77RR8YXCHz7hJ2mRy5aHV%3D7fJOqDnBHA%40mail.gmail.com

src/backend/executor/execTuples.c

@@ -1068,7 +1068,7 @@ const TupleTableSlotOps TTSOpsBufferHeapTuple = {
  *
  *		Basic routine to make an empty TupleTableSlot of given
  *		TupleTableSlotType. If tupleDesc is specified the slot's descriptor is
- *		fixed for it's lifetime, gaining some efficiency. If that's
+ *		fixed for its lifetime, gaining some efficiency. If that's
  *		undesirable, pass NULL.
  * --------------------------------
  */

src/backend/replication/logical/reorderbuffer.c

@@ -1924,7 +1924,7 @@ ReorderBufferAbortOld(ReorderBuffer *rb, TransactionId oldestRunningXid)
 }
 
 /*
- * Forget the contents of a transaction if we aren't interested in it's
+ * Forget the contents of a transaction if we aren't interested in its
  * contents. Needs to be first called for subtransactions and then for the
  * toplevel xid.
  *

src/backend/storage/file/sharedfileset.c

@@ -9,7 +9,7 @@
  * IDENTIFICATION
  *	  src/backend/storage/file/sharedfileset.c
  *
- * SharefFileSets provide a temporary namespace (think directory) so that
+ * SharedFileSets provide a temporary namespace (think directory) so that
  * files can be discovered by name, and a shared ownership semantics so that
  * shared files survive until the last user detaches.
  *

src/bin/pg_dump/pg_backup.h

@@ -11,7 +11,7 @@
  *		as this notice is not removed.
  *
  *	The author is not responsible for loss or damages that may
- *	result from it's use.
+ *	result from its use.
  *
  *
  * IDENTIFICATION

src/bin/pg_dump/pg_backup_archiver.h

@@ -13,7 +13,7 @@
  *		as this notice is not removed.
  *
  *	The author is not responsible for loss or damages that may
- *	result from it's use.
+ *	result from its use.
  *
  *
  * IDENTIFICATION

src/bin/pg_dump/pg_backup_directory.c

@@ -25,7 +25,7 @@
  *	as this notice is not removed.
  *
  *	The author is not responsible for loss or damages that may
- *	result from it's use.
+ *	result from its use.
  *
  * IDENTIFICATION
  *		src/bin/pg_dump/pg_backup_directory.c

src/bin/pg_dump/pg_backup_null.c

@@ -13,7 +13,7 @@
  *		as this notice is not removed.
  *
  *	The author is not responsible for loss or damages that may
- *	result from it's use.
+ *	result from its use.
  *
  *
  * IDENTIFICATION

src/bin/pg_dump/pg_backup_tar.c

@@ -19,7 +19,7 @@
  *		as this notice is not removed.
  *
  *	The author is not responsible for loss or damages that may
- *	result from it's use.
+ *	result from its use.
  *
  *
  * IDENTIFICATION