Remove extra comment at TableAmRoutine.scan_analyze_next_block

The extra comment was accidentally copied here by 6377e12 from
heapam_scan_analyze_next_block().

Reported-by: Matthias van de Meent
Discussion: https://postgr.es/m/CAEze2WjC5PiweG-4oe0hB_Zr59iF3tRE1gURm8w4Cg5b6JEBGw%40mail.gmail.com

Author: akorotkov

src/include/access/tableam.h

@@ -655,16 +655,6 @@ typedef struct TableAmRoutine
 									struct VacuumParams *params,
 									BufferAccessStrategy bstrategy);
 
-	/*
-	 * Prepare to analyze the next block in the read stream.  Returns false if
-	 * the stream is exhausted and true otherwise. The scan must have been
-	 * started with SO_TYPE_ANALYZE option.
-	 *
-	 * This routine holds a buffer pin and lock on the heap page.  They are
-	 * held until heapam_scan_analyze_next_tuple() returns false.  That is
-	 * until all the items of the heap page are analyzed.
-	 */
-
 	/*
 	 * Prepare to analyze block `blockno` of `scan`. The scan has been started
 	 * with table_beginscan_analyze().  See also