Merge branch 'ls/packet-line-protocol-doc-fix' into maint

Correct an age-old calco (is that a typo-like word for calc)
in the documentation.

* ls/packet-line-protocol-doc-fix:
  pack-protocol: fix maximum pkt-line size

Documentation/technical/protocol-common.txt

@@ -67,9 +67,9 @@ with non-binary data the same whether or not they contain the trailing
 LF (stripping the LF if present, and not complaining when it is
 missing).
 
-The maximum length of a pkt-line's data component is 65520 bytes.
-Implementations MUST NOT send pkt-line whose length exceeds 65524
-(65520 bytes of payload + 4 bytes of length data).
+The maximum length of a pkt-line's data component is 65516 bytes.
+Implementations MUST NOT send pkt-line whose length exceeds 65520
+(65516 bytes of payload + 4 bytes of length data).
 
 Implementations SHOULD NOT send an empty pkt-line ("0004").