cmd/pprof/internal/report: fix typo in recognized output unit

Fixes #9814.

Change-Id: I1be49efae0648038f590eeca1262037bf1af3df5
Reviewed-on: https://go-review.googlesource.com/4240Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

src/cmd/pprof/internal/report/report.go

@@ -1531,7 +1531,7 @@ func memoryLabel(value int64, fromUnit, toUnit string) (v float64, u string, ok
 		output, toUnit = float64(value)/1024, "kB"
 	case "mb", "mbyte", "megabyte":
 		output, toUnit = float64(value)/(1024*1024), "MB"
-	case "gb", "gbyte", "giggabyte":
+	case "gb", "gbyte", "gigabyte":
 		output, toUnit = float64(value)/(1024*1024*1024), "GB"
 	}
 	return output, toUnit, true