math/rand: typo fixed in documentation of seedPos

In the comment of seedPost, the word: condiiton was changed to: condition

Change-Id: I8967cc0e9f5d37776bada96cc1443c8bf46e1117
Reviewed-on: https://go-review.googlesource.com/86156Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

src/math/rand/rand.go

@@ -393,7 +393,7 @@ func (r *lockedSource) Seed(seed int64) {
 	r.lk.Unlock()
 }
 
-// seedPos implements Seed for a lockedSource without a race condiiton.
+// seedPos implements Seed for a lockedSource without a race condition.
 func (r *lockedSource) seedPos(seed int64, readPos *int8) {
 	r.lk.Lock()
 	r.src.Seed(seed)