runtime/maps: fix typo in group.go comment (H1 -> H2)

Fixes a typo to correctly describe the hash bits of the control word.

Change-Id: Id3c2ae0bd529e579a95258845f9d8028e23d10d2
GitHub-Last-Rev: 1baa81b
GitHub-Pull-Request: #71730
Reviewed-on: https://go-review.googlesource.com/c/go/+/649416
Reviewed-by: Keith Randall <[email protected]>
Auto-Submit: Keith Randall <[email protected]>
Reviewed-by: Keith Randall <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>
Reviewed-by: Ian Lance Taylor <[email protected]>

Author: acdefgg

Diff for: src/internal/runtime/maps/group.go

@@ -111,7 +111,7 @@ func bitsetShiftOutLowest(b bitset) bitset {
 //
 //	  empty: 1 0 0 0 0 0 0 0
 //	deleted: 1 1 1 1 1 1 1 0
-//	   full: 0 h h h h h h h  // h represents the H1 hash bits
+//	   full: 0 h h h h h h h  // h represents the H2 hash bits
 //
 // TODO(prattmic): Consider inverting the top bit so that the zero value is empty.
 type ctrl uint8