Address second round of feedback

Brain fart on guard clauses when I've been using them all this time...
Updating the conditions made the ternary fall out of favor.

Changed some wording in the doc to suggest the domain name for a
particular NIS server may be different from the bootparamd client's
configuration.

documentation/modules/auxiliary/gather/nis_bootparamd_domain.md

@@ -7,7 +7,7 @@ From the `bootparamd(8)` man page:
 The module documented within will allow a tester to disclose the NIS
 domain name from a server running `bootparamd`. After knowing the domain
 name, the tester can follow up with `auxiliary/gather/nis_ypserv_map` to
-dump a map from an NIS server (running as `ypserv`).
+dump a map from a compatible NIS server (running as `ypserv`).
 
 ## Setup
 
@@ -62,7 +62,8 @@ msf auxiliary(gather/nis_bootparamd_domain) >
 ```
 
 After disclosing the domain name, you can use
-`auxiliary/gather/nis_ypserv_map` to dump a map from an NIS server.
+`auxiliary/gather/nis_ypserv_map` to dump a map from a compatible NIS
+server.
 
 ```
 msf auxiliary(gather/nis_bootparamd_domain) > use auxiliary/gather/nis_ypserv_map

modules/auxiliary/gather/nis_bootparamd_domain.rb

@@ -133,11 +133,9 @@ def parse_bootparams(res)
           Integer  # Router Address: [redacted]
         )
 
-        if host && domain
-          bootparams[host] = domain
-        else
-          break
-        end
+        break unless host && domain
+
+        bootparams[host] = domain
       rescue Rex::ArgumentError
         vprint_status("Finished XDR decoding at #{res.inspect}")
         break

modules/auxiliary/gather/nis_ypserv_map.rb

@@ -136,11 +136,9 @@ def parse_map(res)
           String   # Key: [redacted]
         )
 
-        if status == 1 && key && value
-          map[key] = value
-        else
-          break
-        end
+        break unless status == 1 && key && value
+
+        map[key] = value
       rescue Rex::ArgumentError
         vprint_status("Finished XDR decoding at #{res.inspect}")
         break