Lock: stop logging on every mutex acquisition on Portduino

Before: `Lock::lock()` emitted `LOG_WARN("Lock")` on every successful
acquisition, and `LOG_INFO("Attempt to lock an already locked Lock!")`
whenever the mutex was already held. There are ~300 lock sites in the tree,
and they include the hottest paths on the device: spiLock around every SPI
transaction, cryptLock around every encrypt and decrypt, and deferredLock on
every received packet. So each of those paid a formatted write to the console
before doing its work.

That matters beyond noise on this branch specifically, because the open
question here is radio-thread latency - a false preamble is abandoned after
~8 ms at ShortTurbo, and one CH341 SPI transaction was already measured at
4-8 ms. Logging inside the lock that serialises those transactions puts I/O
on exactly the path being measured, so it has to go before the next round's
numbers mean anything.

The already-locked line also could not do what it claimed. `locked` records
that the mutex is held by somebody, so an ordinary contention between two
threads - the normal case for spiLock - triggers it just as readily as a
thread re-entering its own lock. It logged before blocking, too, so on a
genuine recursive lock it printed and then hung.

After: the Portduino implementation locks and unlocks, and says nothing. The
`locked` field goes with the lines that read it; nothing else used it.

Recursive-lock detection would be worth having, but it needs the owning
thread recorded and compared against the caller, not a bare held flag, and
that is a deliberate change rather than something to slip into a build fix.
Reverting this commit restores the old lines without touching the build fix
underneath it.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01REkPVFh6kvG4AZJ5A8AtM9

src/concurrency/Lock.cpp

@@ -45,14 +45,7 @@ Lock::Lock()
 
 void Lock::lock()
 {
-    if (locked) {
-        LOG_INFO("Attempt to lock an already locked Lock!");
-    }
     pthread_mutex_lock(&mutex);
-    locked = true;
-
-    if (console)
-        LOG_WARN("Lock");
 }
 
 bool Lock::lock(uint32_t)
@@ -66,7 +59,6 @@ bool Lock::lock(uint32_t)
 void Lock::unlock()
 {
     pthread_mutex_unlock(&mutex);
-    locked = false;
 }
 
 Lock::~Lock()

src/concurrency/Lock.h

@@ -41,7 +41,6 @@ class Lock
     SemaphoreHandle_t handle;
 #elif defined(ARCH_PORTDUINO)
     pthread_mutex_t mutex;
-    bool locked = false;
 #endif
 };