Fix misspell in Beats repo

Running `make misspell`.

filebeat/registrar/registrar.go

@@ -155,7 +155,7 @@ func readStatesFrom(in io.Reader) ([]file.State, error) {
 	return states, nil
 }
 
-// fixStates cleans up the regsitry states when updating from an older version
+// fixStates cleans up the registry states when updating from an older version
 // of filebeat potentially writing invalid entries.
 func fixStates(states []file.State) []file.State {
 	if len(states) == 0 {

filebeat/scripts/generator/fields/main.go

@@ -121,8 +121,8 @@ func newField(pattern string) field {
 }
 
 // isValidFormat checks if the input can be split correctly
-// 1. if lenght is 2, the format is {type}:{field.elements}
-// 2. if the lenght is 3, the format is {type}:{field.elements}:{hint}
+// 1. if length is 2, the format is {type}:{field.elements}
+// 2. if the length is 3, the format is {type}:{field.elements}:{hint}
 func isValidFormat(ee []string) bool {
 	return len(ee) == 2 || len(ee) == 3
 }

metricbeat/docs/fields.asciidoc

@@ -6766,7 +6766,7 @@ Kibana instance's health status
 --
 type: long
 
-Number of client connections made to the server. Note that browsers can send multiple simultaneous connections to request mulitple server assets at once, and they can re-use established connections.
+Number of client connections made to the server. Note that browsers can send multiple simultaneous connections to request multiple server assets at once, and they can re-use established connections.
 
 
 --

metricbeat/module/kibana/stats/_meta/fields.yml

@@ -39,7 +39,7 @@
     - name: concurrent_connections
       type: long
       description: >
-        Number of client connections made to the server. Note that browsers can send multiple simultaneous connections to request mulitple server assets at once, and they can re-use established connections.
+        Number of client connections made to the server. Note that browsers can send multiple simultaneous connections to request multiple server assets at once, and they can re-use established connections.
     - name: process
       type: group
       description: >