embed: remove reference to global variables in docs

Refering to variable is both redundant since package scope is used, and
incorrect since global variables are not described in the spec.

Change-Id: Ib08a9f072fc800ee36549f758b68167d8f044878
Reviewed-on: https://go-review.googlesource.com/c/go/+/344214
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Trust: Alexander Rakoczy <alex@golang.org>
Run-TryBot: Alexander Rakoczy <alex@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
diff --git a/src/embed/embed.go b/src/embed/embed.go
index 851cc21..5dcd7f2 100644
--- a/src/embed/embed.go
+++ b/src/embed/embed.go
@@ -83,8 +83,7 @@
 //
 // The //go:embed directive can be used with both exported and unexported variables,
 // depending on whether the package wants to make the data available to other packages.
-// It can only be used with global variables at package scope,
-// not with local variables.
+// It can only be used with variables at package scope, not with local variables.
 //
 // Patterns must not match files outside the package's module, such as ‘.git/*’ or symbolic links.
 // Matches for empty directories are ignored. After that, each pattern in a //go:embed line