fix(userspace): remove unnecessary unsafe blocks around fork/execv

fork() and execv() in libbreenix are safe functions - the unsafe blocks
were unnecessary and caused compiler warnings.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: ryanbreen

userspace/tests/cloexec_test.rs

@@ -43,7 +43,7 @@ pub extern "C" fn _start() -> ! {
     }
     close(write_fd);
 
-    let pid = unsafe { fork() };
+    let pid = fork();
     if pid == 0 {
         let mut fd_buf = [0u8; 21];
         let fd_str = format_u64(read_fd, &mut fd_buf[..20]);
@@ -59,7 +59,7 @@ pub extern "C" fn _start() -> ! {
             core::ptr::null(),
         ];
 
-        let _ = unsafe { execv(program, argv.as_ptr()) };
+        let _ = execv(program, argv.as_ptr());
         println("exec failed");
         exit(1);
     } else if pid > 0 {

userspace/tests/exec_argv_test.rs

@@ -10,7 +10,7 @@ use libbreenix::process::{execv, exit, fork, waitpid, wexitstatus, wifexited};
 pub extern "C" fn _start() -> ! {
     println("=== Exec Argv Test ===");
 
-    let pid = unsafe { fork() };
+    let pid = fork();
     if pid == 0 {
         // Child: exec argv_test with specific args.
         let program = b"argv_test\0";
@@ -19,7 +19,7 @@ pub extern "C" fn _start() -> ! {
         let arg2 = b"world\0" as *const u8;
         let argv: [*const u8; 4] = [arg0, arg1, arg2, core::ptr::null()];
 
-        let _ = unsafe { execv(program, argv.as_ptr()) };
+        let _ = execv(program, argv.as_ptr());
         // If we get here, exec failed.
         println("exec failed");
         exit(1);