Fix spelling errors

Signed-off-by: beorn7 <beorn@grafana.com>

model/histogram/histogram.go

@@ -33,7 +33,7 @@ import (
 //   Positive bucket indices →           |        |           |                          ...     -1         0      1    2    3
 //   Negative bucket indices →  3   2    1        0          -1       ...
 //
-// Wich bucket indices are actually used is determined by the spans.
+// Which bucket indices are actually used is determined by the spans.
 type Histogram struct {
 	// Currently valid schema numbers are -4 <= n <= 8.  They are all for
 	// base-2 bucket schemas, where 1 is a bucket boundary in each case, and

tsdb/chunkenc/chunk.go

@@ -128,7 +128,7 @@ const (
 	ValNone           ValueType = iota // No value at the current position.
 	ValFloat                           // A simple float, retrieved with At.
 	ValHistogram                       // A histogram, retrieve with AtHistogram, but AtFloatHistogram works, too.
-	ValFloatHistogram                  // A floating-point histogram, retrive with AtFloatHistogram.
+	ValFloatHistogram                  // A floating-point histogram, retrieve with AtFloatHistogram.
 )
 
 func (v ValueType) String() string {