time: correct typo in documentation for UnixMicro

Fixes #47283.

Change-Id: Ibdc35433d22be3caa70197b6a95c66999812a16a
GitHub-Last-Rev: 75962b029467a5e26e1ee78a38bf01c954445ea1
GitHub-Pull-Request: golang/go#47284
Reviewed-on: https://go-review.googlesource.com/c/go/+/335549
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Trust: Than McIntosh <thanm@google.com>
diff --git a/src/time/time.go b/src/time/time.go
index 1cf1e2b..4ecc3d8 100644
--- a/src/time/time.go
+++ b/src/time/time.go
@@ -1334,7 +1334,7 @@
 }
 
 // UnixMicro returns the local Time corresponding to the given Unix time,
-// usec milliseconds since January 1, 1970 UTC.
+// usec microseconds since January 1, 1970 UTC.
 func UnixMicro(usec int64) Time {
 	return Unix(usec/1e6, (usec%1e6)*1e3)
 }