database/sql: Fix typos in doc

R=golang-dev
CC=bradfitz, golang-dev
https://golang.org/cl/17590043

src/pkg/database/sql/driver/driver.go

@@ -140,8 +140,8 @@ type Stmt interface {
 }
 
 // ColumnConverter may be optionally implemented by Stmt if the
-// the statement is aware of its own columns' types and can
-// convert from any type to a driver Value.
+// statement is aware of its own columns' types and can convert from
+// any type to a driver Value.
 type ColumnConverter interface {
 	// ColumnConverter returns a ValueConverter for the provided
 	// column index.  If the type of a specific column isn't known

src/pkg/database/sql/sql.go

@@ -201,7 +201,7 @@ type DB struct {
 	connRequests *list.List // of connRequest
 	numOpen      int
 	pendingOpens int
-	// Used to sygnal the need for new connections
+	// Used to signal the need for new connections
 	// a goroutine running connectionOpener() reads on this chan and
 	// maybeOpenNewConnections sends on the chan (one send per needed connection)
 	// It is closed during db.Close(). The close tells the connectionOpener